Of, or relating to glaciers.
Very slow.
Having the appearance of ice.
Cool and unfriendly.
Cold and icy.
A glacial period (colloquially known as an ice age).
Any similar expression used to prevent giving away one's motives, feelings, or situation.
An impassive facial expression cultivated to prevent other players from determining whether one's actions in the game are the result of a quality hand, or of bluffing.